1. Field of the Invention
The invention relates to a method for automatically inserting documents such a microfiches, microfilm jackets or the like to be displayed on a display device and/or copied in a digitizing device. In this method, documents are conveyed one at a time from a holding magazine from a stack of documents to be processed to a document support, and from there to a deposit magazine for the processed documents. The invention, furthermore, relates to a device for carrying out the method.
2. The Prior Art
In light of the fact that the amount of documents that has to be digitized for more comfortable handling and for space reasons in companies, administrative offices and hospitals has grown in the course of time, the time factor plays an important role in connection with the digitizing and filing of such documents.
A commonly employed method for said purpose is to insert the documents individually under the digitizing device by hand and to remove them again manually after they have copied and digitized.
Due to the complicated handling of the documents during feeding, for example when processing microfilm jackets, a put-through of only 30 to 60 jackets per hour can be achieved, which means that new jackets would have to be continually inserted by hand at about 1- to 2-minute intervals. This requires the constant presence of a person while the digitizing device is being operated.
Patent application 198 46 899.7 describes an automated method and a device adapted to said method. It is possible with the help of said method and device to significantly increase the processing speed. The device described in said patent operates with purely mechanical means, which makes the device susceptible to trouble and maintenance-intensive.
Therefore, the invention is based on the problem of controlling or designing a method and a device of the type specified above in such a manner that the expenditure in terms of engineering expenditure remains low; that only a few moving parts are present; and that a reliable mode of operation is achieved nonetheless.
The invention solves this problem in that the top document is lifted up by suction from a stack of documents contained in a holding magazine, to about the level of the document support, and the remaining stack is subsequently kept in the holding magazine by suction in the opposite direction; the document pulled up by suction is then transported to the document support sideways and deposited on the document support by cancelling the suction effect. After the document has been processed, it is lifted up again by suction and transported to the deposit magazine.
A possible way of controlling the method is represented by the following sequence:
The holding magazine is filled.
No document is present on the document support.
The deposit magazine is emptied.
The pump generating the suction effect is shut off.
The suction element is positioned above the filled magazine, while the depositing element is positioned above the still-empty deposit magazine.
The suction device is started.
At least one document is lifted from the stack by suction.
This causes the vacuum to rise and a limit pressure valve is opened.
Any other document that may adhere to the document is removed and sucked back into the magazine; the remaining stack is retained.
The vacuum is controlled down to a lower value.
The document lifted by suction is displaced sideways to the document support.
The suction device is shut off (so that the vacuum will rapidly break down; either a bypass valve is opened and the outlet side of the suction device is briefly closed, or the drive of the suction device is slowed down electrically or mechanically).
The vacuum breaks down; the document drops onto the document support.
The document is digitized.
Following digitizing, the document is lifted from the document support by suction effect as well and transported to the deposit magazine.
Simultaneous with the lifting of the digitized document from the document support, the next document is collected from the holding magazine by suction.
According to a preferred way of controlling the method, in connection with which the limit pressure valve and the second conveyor means transporting the processed document from the document support to the deposit magazine are omitted, the operational sequence is as follows:
The holding magazine is filled.
No document is present on the document support.
The deposit magazine is emptied.
The transport means lifting the document by suction is positioned on top of the filled magazine.
The suction device located in the transport means is started.
At least one document is lifted from the stack by suction.
The suction openings in the transport means are closed, which either actuates a microswitch arranged within the zone of said suction openings, said microswitch generating a signal for cancelling the return suction effect (such a sensor may be located also in another site).
The documents lifted by suction is displaced sideways to the document support.
The suction device in the transport means is shut down.
The vacuum breaks down; the document drops onto the document support.
The transport means is driven away from the document support sideways.
The document is digitized.
Following digitizing, the document is again picked up from the document support by the transport means and transported to the deposit magazine.
After the transport means has ejected the processed document into the deposit magazine, it drives back into the original position above the holding magazine and the sequence starts anew.
A device according to a preferred embodiment is employed in connection with this second variation of the method. This device is characterized in that the plane board provided with the suction openings is part of a housing that is displaceable on guides and divided in two part areas by means of a partition wall, whereby one of the part areas is arranged located above the suction openings and can be evacuated by means of a suction blower arranged in the second part area, whereby the second part area has an opening that is aligned with an opening in the holding magazine so that the air aspirated from the first part area is received in the double-walled bottom part of the holding magazine.
This means that as long as no document adheres to the plane board, covering the suction openings located there, the air moved by the suction blower circulates through the openings in the double-walled bottom area that are aligned with each other, and from there through the openings in the side walls of the magazine and then through the suction openings in the plane board to the suction blower.
Now, when a document engaged by suction adheres to said plane board, the suction openings are closed and the flow of air is interrupted.
A second suction blower located in the bottom zone of the holding magazine is now activated, causing the inner cavity in the holding magazine to be evacuated, so that the remaining stack present in the container is retained and only one single document actually adheres to the plane board of the transport means. As stated above, provision may be made in the plane board for a microswitch serving as the means for triggering the second suction blower, said microswitch being pressed through the document engaged by suction.
Such a microswitch, furthermore, offers the advantage that the document is actively repelled by spring force of said microswitch, which supports the effect of gravity.
A second possibility for triggering the second suction blower is to make provision in the flow of air of the first suction blower for a microswitch that is deflectable against the force of a spring. Said microswitch pivots back into its switching position when the flow of air is interrupted as a document is being engaged by suction.
The aspirated document is deposited on a document support which, according to a further embodiment, preferably comprises a framework corresponding with the document. A glass panel covering the document is pivot-mounted on this frame.
The glass panel needs to be arranged on the frame only when required because it is not absolutely required when microfiches are digitized, but needed for digitizing microfilm jackets.
According to a further embodiment, the frame consists of hollow profiles, whereby the profile walls disposed on the inner side have openings at their ends pointing at the document, and the cavities in the hollow profiles can be evacuated. The profile walls of the frame disposed on the inner side have a defined inclination, so that when the document to be digitized drops down, a self-centering effect is achieved. As soon as the document is positioned in the frame, the cavities of the frame are evacuated, so that a vacuum is generated below the document that flatly presses the document against the support.
As stated above, the vacuum suffices for completely pressing a microfiche plane against the support without the need of having to place a glass panel on the microfiche.
When a microfilm jacket is processed, the application of the vacuum causes the underside of the microfilm jacket to be pressed against the support. However, the pocket-shaped receiving strips for receiving the document do not possess such planeness, so that it is necessary in this case to additionally attach a glass panel.
After the digitizing process has been completed, the glass panel is swiveled away upwards. The vacuum below the document is still maintained so that the document cannot remain adhered to the glass panel driving up.
As soon as the glass panel has been swiveled away to the rear, the transport means drives on top of the document support and engages the digitized document by suction. On the way to the holding magazine, the transport means ejects the documents above the deposit magazine. According to claim 20, the deposit magazine is located on the bottom of a housing that is provided with an opening at its upper side corresponding with the dimensions of the document. A guide means is extending from said opening to the deposit magazine. Said guide means is designed in such a way that the document dropping through the opening describes a path turning the document by 180xc2x0.
According to a further embodiment, the glass panel flattening the documents is secured with play on two U-shaped cantilevered arms. The cantilevered arms can be pivoted by means of an electric motor, swiveling from the covering position to a release position. The U-shaped cantilevered arms extend beyond the profile of one side of the frame of the document support. A driving means is secured on the shaft of the electric motor. During rotation, the driving means takes along a pin secured on one of the cantilevered arms, thereby causing the glass plate secured on the cantilevered arms to be pivoted upwards.
This construction has the advantage that the glass panel can be pivoted upwards by hand as well without actuating the motor.
The glass panel must not be supported in any rigid manner so as to assure that it will always rest plane on the document in each case.
According to a further embodiment, the glass panel is secured on the cantilevered arms by means of a ribbon that is adhesive on both sides. This adhesive ribbon is elastic and acts like another bearing permitting a smaller angular clearance. The bearings of the cantilevered arms have a certain play as well.
In addition, near the adhesive connection, the cantilevered arms may comprise an additional joint permitting a clearance of a few angular degrees.
According to a further embodiment, the deposit magazine is arranged located between the holding magazine and the document support. This results in shorter distances for the transport means to travel.
However, it is possible also, according to a further embodiment, that the document support is arranged between the holding magazine and the deposit magazine. Especially in connection with such an embodiment, provision is made according to a further embodiment that a second transport means is provided for transporting the document from the document support to the deposit magazine. The second transport means is capable of pivoting by an angle of about 150xc2x0 anticlockwise, and by about 210xc2x0 clockwise, in a plane extending perpendicular to the plane of the document support. The advantage of such an embodiment lies in that as the processed document is being picked up by said second transport means, the first transport means is capable of engaging by suction a new document for digitizing.
The second transport means pivots the document it has picked up by suction in such a manner that it comes to rest in a slanted plane. When the suction effect is cancelled, the document can then slide from there into the deposit magazine under the influence of gravity, coming to rest in the deposit magazine turned by 180xc2x0 in relation to its starting position. As also in connection with the first alternative, what is achieved in this way is that the processed documents can be collected again from the deposit magazine in the same sequence, i.e. the documents are deposited in the deposit magazine in the same order as in the holding magazine.
According to a further embodiment, in the course of the pivoting movement of the second transport means, slots provided in the pivot guide open and then connect the suction opening or openings in the board with the suction device or separate such opening(s) from the latter.
In connection with a transport means of the last-mentioned type, it is possible to primarily establish a connection with the atmosphere by way of closable openings positioned above the suction openings in the transport means. The release of the document from the slanted board of the transport means is supported and facilitated in this way by the effect of gravity.
With all variations of the invention, it is absolutely necessary for the xe2x80x9cseparationxe2x80x9d function for separating the documents in the holding magazine that a gap is available between the board provided with the suction openings and the top edges of the side parts of the holding magazine. Without such a gap, it is not possible to remove another documentxe2x80x94which may adhere to the first document previously engaged by suctionxe2x80x94by suction in the opposite direction. The width of the gap can be set by means of elevations provided on the top edges of the side parts. Such elevations may serve at the same time as guides for displacing the board sideways.
However, it is preferred that provision is made that such gap areas are produced, for example by wheels on which the transport means can be driven. The wheels are dimensioned in such a way that the bottom clearance of the transport means is adequate for producing the gap.